Retro + faux, something which references a fake/non-existent past. Used to describe an object or especially a place/area which is made to evoke a version of the past which only ever existed in popular imagination and not in reality.

"Meh, that Wild West theme park was totally retreaux"
"How so?"
"I'm pretty sure not everyone in those days had to choose between being a cowboy, outlaw, grizzled old prospector, or working in a saloon."